Mine-door



No Model.)

C. SWAN 8v G. M. WHAITE.

MINE DOOR. Patemted July 21, 1891.

UNITED STATES PATENT OFFICE.

CHARLES SWAN AND GEORGE M. VHAITE, OF GLENBURN, ILLINOIS.

MINE-DOOR.

SPECIFICATION forming part of Letters Patent No. 456,446, dated July 21,1891:

Application tiled April 24, 1890.

To alt whom t may concern:

Be it known that we, CHARLES SWAN and GEORGE M. WHAITE, citizens of theUnited States, residing at Glenburn, in the county of Vermilion andState of Illinois, have invented a new and useful Mine-Door, of whichthe following is a specification.

This invention relates to improvements in mine-doors.

The objects and advantages of the invention, together with the novelfeatures thereof, will appear in the following description, and beparticularly pointed out in the claim.

Referring to the drawings, Figure l is a perspective of a mine-doorconstructed in accordance with our invention. Fig. 2 is a transverseview through the door; Fig. 3, a transverse section through the hinge.Fig. 4C is a vertical longitudinal section of one of the cylinders.

Like numerals indicate like parts in all the figures of the drawings.

l represents the usual rails forming the track, which rails are mountedupon a series of cross-ties 2, one of which is provided with a strip3combining therewith to form a sill.

At one side of the track and running parallel thereto is a side sill 4,from the center of which, opposite the end of the sill 3, rises thehinge-post 5, and at the opposite side of the track and end of thedoor-sill 3 is located a second vertical post (i, the two posts beingconnected at theirupper ends by a transverse narrow strip 7. The posts 5and 6 are cylindrical, as shown, and the opposite edges of the door l0are rounded, as at O, which door is designed to exactly fit between thestrips 7 and door-sill and the posts 5 and G, and by reason of the postbeing cylindrical and the edges of the door being curved a substantiallyair-tight joint or connection is effected between the doorand frame. Thehinge-post 5 is transversely perforated near its upper and lower ends,and through the same are passed L-shaped bolts l2, the rear threadedends of which are provided with nuts 13 and the inner L-shaped ends ofwhich are turned inwardly toward each other and take into and bear inopenings 14, formed in the adjacent ends or bottom and top,respectively, of an upper and lower recess l5, formed in the hinge-edgeof the door, the bearing ends of Serial No. 349,314. (No model.)

said recesses being surrounded by metallic straps 1G, bolted to theopposite faces of the door.

Mounted upon the hinge-post 5 is a cross-l arm 17 ,which extendsparallel with the track and sill 4, and in the ends of the posts thereis swiveled a Ysheaf and pulley 1S, below which and mounted upon thesill 4 is a pair of vertical cylinders 19, one of which is hid by thedoor, provided at their upper -ends with removable caps 20, centrallyperforated, as at 2l, and into said cylinders extend the terminals ofdoor-operating ropes 22, the inner ends of which are, after having beenpassed over pulleys, connected to perforated studs 23, secured to theopposite sides of the door. The opposite ends of the ropes are connectedto weighted pistons 24, having air-tight connections with the walls ofthe cylinders by means of a suitable packing 25, surrounding thepistons, which packing is preferably formed by a series of rubber ringslocated in an annular recess formed upon the piston. At or near thelower end of each of the cylinders there is located a valve 2G,perforated and adapted to open upwardly, through v which air is drawnwhen the door is opened in either direction by reason of the pistonheadacting to form a vacuum, which air is compressed by the returning pistonwhen the door .is closed by the latter and forms a cushion for thepiston, so that the door moving in either direction does socomparatively slowly. By regulating the movement of the valve 2G in asuitable way the escape and admission of air may be regulated, and inthis way the ease with which the door may be operated is acquired. Adoor thus constructed requires no attention, and may be readily operatedby a mules head coming in contact with the same in either direction. Incase of accident in the mine the door will not in any way interfere withthe ready escape of the miners, as it will open as well from eitherdirection and to its entire capacity. The simplicity of the constructionwarrants its durability and cheapness of construction. u

Having described our invention, what we claim is- In a mine-door, thecombination, with the doonframe comprising opposite posts, of a doorhaving opposite rounded edges and iit- TOO ting` the frame, one edge ofthe door being the outer ends ofthe bolts for securing,` them providedwith a pair of recesses, the top of adjustably and removably in place,substanone recess and bottom of the other recess hetially set forth.

ing provided with bearing-openings, metallic In testimony that we claimthe foregoing as 15 5 straps embracing the parts of the door in ourownwehave hereto affixed our signatures which said openings are formed andsecured in presence of tWo Witnesses.

to the opposite faces of the door, opposite CHARLES SVAN.inwardly-disposed L-shaped bolts passed GEORGE M. VHAITE. through theadjacent cylindrical post and Nitnessesz 1o having their inner endsterminating in the CHARLES A. ROGERS,

bearing-openings of the recesses, and nuts on JAMES A. ROGERS.

